docs: def do_where(self, taskid: int) -> None:
          """Show stack frames for a task"""
          task = task_by_id(taskid, self._loop)
          if task:
              self._sout.write(_format_stack(task))
              self._sout.write('\n')
          else:
              self._sout.write('No task %d\n' % taskid)